Polishing Pad

ABSTRACT

The present invention provides a polishing pad, and is more particularly related to a polishing pad, the width of groove bottom of polishing surface of which is 0 mm. The polishing pad includes a polishing surface on which comprises a plurality of grooves, wherein each groove includes a groove opening and a groove bottom, the characteristic of which being that the width of groove bottom of polishing surface is 0 mm. Therefore, when the polishing step is performed, it is not easy for polishing particles suspended in the slurry to deposit on the groove bottom and the deposits can be prevented from scratching the concerned work piece to avoid damage of work piece.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is related to a polishing pad, and moreparticularly, to a polishing pad, the width of groove bottom ofpolishing surface of which is 0 mm.

2. Description of the Prior Art

Electrical chips are formed by deposition of various laminate materials,for example, a silicon wafer is one of the substrates of laminatematerials. Whenever a new laminate is deposited, a polishing orscratching step is often needed for removing excessive laminatematerials to planarize the chip or to achieve other purposes. Suchprocess of polishing is generally called chemical mechanical polishing(CMP). Since chips are formed by deposition of different thin filmlaminates, the CMP step needs to be performed for multiple times forevenly removing excessive laminate materials from the surface of a chipto achieve the purpose of planarization.

And usually when the CMP step is performed, chemical slurry is led inbetween the chip and the polishing pad for generating chemical reactionbetween the deposited thin film laminates and the chemical slurry or forgenerating mechanical reaction between the deposited thin film laminatesand the particles in the chemical slurry to remove part of excessivethin film laminates on the surface of chip. However, the slurry existingbetween the polishing pad and the chip makes it easy for the polishingpad and the chip to become fully attached to each other, which thuscauses disappearance of the force of friction between the polishing padand the chip. Therefore, in order to achieve better polishing effectwith the CMP step, the most common practice at present is to installgroove on the surface of the polishing pad not only for increasing forceof friction between the polishing pad and the chip but also for ensuringthat the slurry is evenly distributed on the surface of the polishingpad and for letting polishing particles suspended in the slurry and thescraps to flow out through the groove.

However, in the common practice, when groove is installed on the surfaceof the polishing pad, there will be near-90-degree right-angleindentations on the bottom of the groove, as shown in FIG. 1. Thereforewhen the CMP step is performed, it is easy for the polishing particlesin the slurry or the scraps produced by the polishing process to depositin the corners of indentations without flowing out. The residualpolishing particles or deposits will form larger particles and lead toscratching or damaging of surface of the polished object.

SUMMARY OF THE INVENTION

In order to solve the problems as described above, one objective of thepresent invention is to provide a polishing pad, the width of groovebottom of polishing surface of which is 0 mm to prevent the concernedwork piece from being scratched and thus damaged by larger particlesformed by polishing particles suspended in the slurry or scraps producedafter polishing depositing on the bottom of groove.

Another objective of the present invention is to provide a polishingpad, the design of bottom of groove of polishing surface of whichfacilitates the flow of the slurry.

Still another objective of the present invention is to provide apolishing pad, the groove of which ensures that the slurry is evenlydistributed on the polishing surface.

According to the above objectives, the present invention provides apolishing pad, the width of bottom of groove of polishing surface ofwhich is 0 mm. The polishing pad includes a polishing surface on whichcomprises a plurality of grooves, wherein each groove includes a grooveopening and a groove bottom, the characteristic of which being that thewidth of groove bottom of polishing surface is 0 mm. Therefore, when thepolishing step is performed, it is not easy for polishing particlessuspended in the slurry to deposit on the groove bottom and the depositscan be prevented from scratching the concerned work piece to avoiddamage of work piece.

Therefore, with the design of width of groove bottom being 0 mm of thepolishing pad provided by the present invention, not only can thedeposition of polishing particles or scraps produced after polishing onthe bottom of groove that may lead to scratching and damaging of workpiece be prevented, but the flow of slurry can also be facilitated sincethe design of groove bottom prevents too much slurry from accumulatingin the groove and thus achieves better polishing effect.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention as well as a preferred mode of use, further objectives andadvantages thereof will best be understood by reference to the followingdetailed description of illustrative embodiments when read inconjunction with the accompanying drawings, wherein:

FIG. 1 is a sectional view of a polishing pad (prior art);

FIG. 2 is a front view of a polishing pad;

FIG. 3A is a sectional view of groove of a polishing pad;

FIG. 3B is a sectional view of groove of a polishing pad;

FIG. 3C is a sectional view of groove of a polishing pad; and

FIG. 3D is a sectional view of groove of a polishing pad.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention discloses a polishing pad, and more particularly,a polishing pad with the width of groove bottom of polishing surface ofwhich being 0 mm. In the present invention, some details formanufacturing or processing polishing pad are achieved by applyingconventional art, and therefore are not completely depicted in belowdescription. And the drawings referred to in the following are not madeaccording to the actual related sizes, the function of which is only toexpress and illustrate characteristics of the present invention.

FIG. 2 is a view of a preferred embodiment of polishing pad of thepresent invention. The polishing pad 20 includes a polishing surface 21and a plurality of grooves 22 are disposed on the polishing surface 21,wherein each groove 22 includes a groove opening 221 and a groove bottom222, as shown in FIG. 3A taken along section line a-a′ in FIG. 2, thecharacteristic of which being that the width of groove bottom 222 ofpolishing surface 21 is 0 mm.

FIG. 3A is a view of a preferred embodiment of groove of polishing padaccording to the present invention. Between the groove opening 221 andthe groove bottom 222 of the polishing pad 20 comprises at least onesection 223, and the width of groove opening 221 and the width of groovebottom 222 are different, wherein between each section 223 comprises abend to form an included angle. Thus part of section 223 can be a planesurface perpendicular to the groove bottom 222, and part of section 223can be an inclined plane that is not perpendicular to the groove bottom222.

FIG. 3B is a view of another preferred embodiment of groove of polishingpad according to the present invention. Between the groove opening 221and the groove bottom 222 of the polishing pad 20 comprises at least onesection 223, and the width of groove opening 221 and the width of groovebottom 222 are different, wherein the section 223 is V-shaped and isthus an inclined plane that is not perpendicular to the groove bottom222.

FIG. 3C is a view of still another preferred embodiment of groove ofpolishing pad according to the present invention. Between the grooveopening 221 and the groove bottom 222 of the polishing pad 20 comprisesat least one section 223, and the width of groove opening and the widthof groove bottom are different, wherein between the polishing surface 21and the section 223 comprises a bent to form an included angle A1,degree of angle A1 being between 90 to 120 degrees.

FIG. 3D is a view of yet another preferred embodiment of groove ofpolishing pad according to the present invention. Between the grooveopening 221 and the groove bottom 222 of the polishing pad 20 comprisesat least one section 223, and the width of groove opening and the widthof groove bottom are different, wherein the section 223 is U-shaped andthe curved groove bottom thus facilitates the flow of slurry.

The present invention further provides still another preferredembodiment of groove of a polishing pad. Between the groove opening andthe groove bottom of the polishing pad comprises at least one section,and the width of groove opening 221 and the width of groove bottom 222are different, wherein the section is an irregular curved surface.

The aforementioned polishing pad can further include a connectingsurface for being connected to a polishing surface of another polishingpad to form a two-layer polishing pad.

With the design of width of groove bottom of the polishing pad providedby the present invention being 0 mm, not only can the polishingparticles or scraps produced after polishing be prevented fromdepositing on the groove bottom and thus leading to scrap and damage ofwork piece by the deposits, but the design of groove bottom alsofacilitates the flow of slurry so that excessive amount of slurry willnot accumulate in the groove and better polishing effect can beachieved.

What are described above are only preferred embodiments of the presentinvention and are not for limiting the scope of the present invention;and the above description can be understood and put into practice bythose who are skilled in the art. Therefore any equivalent modificationsand arrangements made without departing from the spirit disclosed by thepresent invention should be encompassed by the appended claims accordedwith the broadest interpretation.

1. A polishing pad, said polishing pad including a polishing surface,said polishing surface comprising a plurality of grooves on it, whereinsaid each groove includes a groove opening and a groove bottom, thecharacteristic of said polishing pad being in that width of said groovebottom of said polishing surface is 0 mm.
 2. The polishing pad accordingto claim 1, wherein between said groove opening and said groove bottomof said polishing pad comprises at least one section.
 3. The polishingpad according to claim 2, wherein said section is V-shaped.
 4. Thepolishing pad according to claim 2, wherein said section is U-shaped. 5.The polishing pad according to claim 2, wherein between each saidsection comprises a bend to form an included angle.
 6. The polishing padaccording to claim 2, wherein between said polishing surface and saidsection comprises a bend to form an included angle.
 7. The polishing padaccording to claim 6, wherein degree of said included angle is about90˜120 degrees.
 8. The polishing pad according to claim 2, wherein saidsection is a plane surface perpendicular to said groove bottom.
 9. Thepolishing pad according to claim 2, wherein said section is an inclinedplane not perpendicular to said groove bottom.
 10. The polishing padaccording to claim 2, wherein said section is an irregular curvedsurface.
 11. The polishing pad according to claim 1, wherein width ofsaid groove opening and width of said groove bottom of said polishingpad are different.
 12. The polishing pad according to claim 1, whereinsaid polishing pad further includes a connecting surface for beingconnected to polishing surface of another polishing pad.